1) In the first days, close basic food, energy and water deficits — don't let satisfaction collapse. Check the material balance on the Economy tab and build to cover shortfalls.
2) Keep school, hospital and housing coverage at 70%+ (Population tab). Diversify industry to lower unemployment.
3) Set storage targets; don't stockpile goods you can't export. Don't neglect logistics and internet infrastructure.
4) Start research early (schools, universities and labs produce research points). Robotic and AI variants ease the pressure on your workforce.
5) Before going to war, check your soldiers, officers, equipment and mobilization stock. Economic absorption (driving a rival to bankruptcy and taking its factories) is usually stronger than war.
6) In diplomacy, join a coalition against a major aggressor and nurture relations with treaties. In this wiki every material and building is clickable — follow the chain.